Desoldering those original switches could've been a big mistake if they were in good condition! Those are very likely old cherry MX brown-stem switches, known as "vintage browns" (or "vint browns"). Not only are they excellent light tactiles, they are relatively rare. You can swap in a new set of springs for greater consistency between keys, and lubricate the slider part of the stem with an overengineered oil such as Krytox GPL 104 or VPF 1514.

Plus this board is a plateless design. The classic Cherry "dry" click-clack sound works perfectly with it, and the plastic case and switches mounted directly on PCB contribute a bouncy feel that prevent prevents the tactile switches from feeling too jarring, which I think is a common flaw when combining tactile switches and a very rigid plate+PCB arrangement in a metal custom.

Milky-top Gateron is almost never a bad choice, but unless you absolutely hate tactile switches then you really should just keep the originals.

My MX-11800 was one of the first keyboards I ever customized, and it's still one of my favorites in my collection.

That said I agree with the other comments about the layout, it's really not comfortable to use the trackball, nor the keys above it in the upper-right corner.